vc++实现文件加密解密

#include "stdafx.h"
#include "ecfile.h"
#include "ecfileDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
 CAboutDlg();

// Dialog Data
 //{{AFX_DATA(CAboutDlg)
 enum { IDD = IDD_ABOUTBOX };
 //}}AFX_DATA

 // ClassWizard generated virtual function overrides
 //{{AFX_VIRTUAL(CAboutDlg)
 protected:
 virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
 //}}AFX_VIRTUAL

// Implementation
protected:
 //{{AFX_MSG(CAboutDlg)
 //}}AFX_MSG
 DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
 //{{AFX_DATA_INIT(CAboutDlg)
 //}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
 CDialog::DoDataExchange(pDX);
 //{{AFX_DATA_MAP(CAboutDlg)
 //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
 //{{AFX_MSG_MAP(CAboutDlg)
  // No message handlers
 //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CEcfileDlg dialog

CEcfileDlg::CEcfileDlg(CWnd* pParent /*=NULL*/)
 : CDialog(CEcfileDlg::IDD, pParent)
{
 //{{AFX_DATA_INIT(CEcfileDlg)
 m_path = _T("");
 m_pass = _T("");
 //}}AFX_DATA_INIT
 // Note that LoadIcon does not require a subsequent DestroyIcon in Win32
 m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CEcfileDlg::DoDataExchange(CDataExchange* pDX)
{
 CDialog::DoDataExchange(pDX);
 //{{AFX_DATA_MAP(CEcfileDlg)
 DDX_Text(pDX, IDC_PASSWORD, m_path);
 DDX_Text(pDX, IDC_PASS1, m_pass);
 //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CEcfileDlg, CDialog)
 //{{AFX_MSG_MAP(CEcfileDlg)
 ON_WM_SYSCOMMAND()
 ON_WM_PAINT()
 ON_WM_QUERYDRAGICON()
 ON_BN_CLICKED(IDC_E, OnE)
 ON_BN_CLICKED(IDC_D, OnD)
 ON_BN_CLICKED(IDC_BROW, OnBrow)
 //}}AFX_MSG_MAP
END_MESSAGE_MAP()

BOOL CEcfileDlg::OnInitDialog()
{
 CDialog::OnInitDialog();

 ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
 ASSERT(IDM_ABOUTBOX < 0xF000);

 CMenu* pSysMenu = GetSystemMenu(FALSE);
 if (pSysMenu != NULL)
 {
  CString strAboutMenu;
  strAboutMenu.LoadString(IDS_ABOUTBOX);
  if (!strAboutMenu.IsEmpty())
  {
   pSysMenu->AppendMenu(MF_SEPARATOR);
   pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
  }
 }

 SetIcon(m_hIcon, TRUE);
 SetIcon(m_hIcon, FALSE);

 return TRUE;
}

void CEcfileDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
 if ((nID & 0xFFF0) == IDM_ABOUTBOX)
 {
  CAboutDlg dlgAbout;
  dlgAbout.DoModal();
 }
 else
 {
  CDialog::OnSysCommand(nID, lParam);
 }
}

void CEcfileDlg::OnPaint()
{
 CDialog::OnPaint();
}

HCURSOR CEcfileDlg::OnQueryDragIcon()
{
 return (HCURSOR) m_hIcon;
}

void CEcfileDlg::OnE()
{
 UpdateData(TRUE);
 if(m_path == "")
 {
  AfxMessageBox("怎么没有选择要加密的文件就开始加密啊?");
  return;
 }

 UpdateData(TRUE);
 if(m_pass == "")
 {
  AfxMessageBox("没有写上密码");
  return;
 }

 if(ecfile(m_path))
 {
  MessageBox("加密成功了已经");
 }
 else
 {
  MessageBox("没加密成功");
 }
}

void CEcfileDlg::OnD()
{
 UpdateData(TRUE);
 if(m_path == "")
 {
  AfxMessageBox("怎么没有选择要加密的文件就开始解密啊?");
  return;
 }

 UpdateData(TRUE);
 if(m_pass == "")
 {
  AfxMessageBox("没有写上密码");
  return;
 }

 if(dcfile(m_path))
 {
  MessageBox("解密成功了");
 }
 else
 {
  MessageBox("解密失败了");
 }
}

void CEcfileDlg::OnBrow()
{
 CFileDialog dlg(TRUE);
 if(dlg.DoModal() == IDOK)
 {
  m_path = dlg.GetPathName();
  UpdateData(FALSE);
 }
 else
 {
  return;
 }
}

//给文件加密的函数
BOOL CEcfileDlg::ecfile(LPCTSTR fpath)
{
 char *data;
 CFile *file;
 DWORD flen;

 m_password = epass();

 file = new CFile;
 if ( !file->Open(fpath, CFile::shareDenyNone|CFile::modeReadWrite))
 {
  return FALSE;
 }

 flen = file->GetLength();
 data = new char[(int)flen];

 file->SeekToBegin();
 file->Read(data, flen);

 for(int i=0; i<(int)flen; i++)
 {
  data[i] ^= m_password;
  data[i] ^= flen;
 }

 file->SeekToBegin();
 file->Write(data, flen);
 delete[] data;

 //添加密码验证信息
 char cpass[5] = "love";
 for(int j=0; j<5; j++)
 {
  cpass[j] ^= m_password;
 }
 file->SeekToEnd();
 file->Write(&cpass, 5);
 file->Close();
 delete file;

 return TRUE;
}

//给文件解密的函数
BOOL CEcfileDlg::dcfile(LPCTSTR fpath)
{
 char *data;
 CFile *file;
 DWORD flen;
 char love[5];

 file = new CFile;
 if( !file->Open(fpath, CFile::shareDenyNone|CFile::modeReadWrite))
 {
  return FALSE;
 }

 flen = file->GetLength();
 data = new char[(int)flen];

 //检验密码是不是正确
 file->Seek(-5, CFile::end);
 file->Read(&love, 5);

 m_password = epass();

 for(int i=0; i<5; i++)
 {
  love[i] ^= m_password;
 }

 if(strcmp(love, "love")!=0)
 {
  return FALSE;
 }

 //解密
 file->SeekToBegin();
 file->Read(data, flen);

 for(int j=0; j<(int)flen; j++)
 {
  data[j] ^= m_password;
  data[j] ^= (flen-5);
 }
 file->SeekToBegin();
 file->Write(data, flen);
 file->SetLength(flen-5);
 file->Close();

 delete[] data;
 delete file;
 return TRUE;
}

//获得密码的函数
__int64 CEcfileDlg::epass()
{
 DWORD plen;
 char *ppass;
 __int64 mc= 8757735233305;
 UpdateData(TRUE);

 ppass = m_pass.GetBuffer(0);

 plen = strlen(ppass);

 for(int i=0; i<(int)plen; i++)
 {
  mc ^= ppass[i]|128;
 }
 return mc;
}